Editorial
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Sep 26, 2015; 7(8): 1078-1089
Published online Sep 26, 2015. doi: 10.4252/wjsc.v7.i8.1078
Emerging role of microRNAs in cancer stem cells: Implications in cancer therapy
Minal Garg
Minal Garg, Department of Biochemistry, University of Lucknow, Lucknow 226007, India
Author contributions: Garg M solely contributed to this paper.
Conflict-of-interest statement: Author declares no potential conflicts of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Minal Garg, Msc, PhD, Assistant Professor, Department of Biochemistry, University of Lucknow, University Road, Lucknow 226007, India. minal14@yahoo.com
Telephone: +91-9335820857
Received: January 24, 2015
Peer-review started: January 24, 2015
First decision: March 6, 2015
Revised: June 27, 2015
Accepted: August 20, 2015
Article in press: August 21, 2015
Published online: September 26, 2015
Abstract

A small subset of cancer cells that act as tumor initiating cells or cancer stem cells (CSCs) maintain self-renewal and growth promoting capabilities of cancer and are responsible for drug/treatment resistance, tumor recurrence and metastasis. Due to their potential clinical importance, many researchers have put their efforts over decades to unravel the molecular mechanisms that regulate CSCs functions. MicroRNAs (miRNAs) which are 21-23 nucleotide long, endogenous non-coding RNAs, regulate gene expression through gene silencing at post-transcriptional level by binding to the 3’-untranslated regions or the open reading frames of target genes, thereby result in target mRNA degradation or its translational repression and serve important role in several cellular, physiological and developmental processes. Aberrant miRNAs expression and their implication in CSCs regulation by controlling asymmetric cell division, drug/treatment resistance and metastasis make miRNAs a tool of great therapeutic potential against cancer. Recent advancements on the biological complexities of CSCs, modulation in CSCs properties by miRNA network and development of miRNA based treatment strategies specifically targeting the CSCs as an attractive therapeutic targets for clinical application are being critically analysed.

Keywords: Cancer stem cells, Drug resistance, Tumor recurrence, MicroRNAs, Cancer therapy

Core tip: Cancer stem cells (CSCs) which are believed to be the prerequisite for metastasis and tumor recurrence, are endowed with ability to undergo symmetric cell division, capacity for self-renewability, long term proliferation and resistance to anti-neoplasic therapeutic drugs. Regulatory characteristics of microRNAs (miRNAs) which are the clusters of non-coding RNA molecules, include widespread changes in gene expression through gene silencing at post-transcriptional level and are dysregulated in human cancer. Over the past two decades, miRNAs have gained widespread attention due to their involvement in acquisition of stem cell-like properties, regulation and reprogramming by cancer cells during cancer progression. Many studies are coming up which document miRNAs as novel therapeutic tool in targeting CSCs functions, sensitizing them to apoptotic effects of anti-cancer drugs, and reducing tumor burden with no relapse in current clinical settings.